Elevation of KIR+CD8+ T cells during human pregnancy

Résumé fourni par la source

Abstract Recently, we identified KIR+CD8+ T cells as a previously underappreciated regulatory subset important in humans and mice to suppress self-reactivity, especially in the context of infections. To better understand what other roles these cells might play, we asked whether they are active during pregnancy. We first observed an increased frequency of KIR+CD8+ T cells in the peripheral blood of pregnant women at the second trimester compared to age-matched nonpregnant females. Women with a male fetus had a significantly higher level of KIR+CD8+ T cells than those with a female fetus. In vitro, KIR+CD8+ T cells suppressed HY-specific CD8+ T cells only from mothers with a male fetus. Therefore, the higher induction of KIR+CD8+ T cells in mothers carrying a male fetus may suppress the additional allogenic immune responses triggered by the Y chromosome from the male fetus. Longitudinal analysis over pregnancy showed that KIR+CD8+ T cells undergo expansion and differentiate into functional cytotoxic cells during pregnancy, and that their levels are maintained postnatally. In addition, increased levels of KIR+CD8+ T cells correlated with pregnancy disorders. Taken together, our findings suggest an important role of KIR+CD8+ T cells in the maintenance of maternal tolerance by suppressing fetal-specific alloreactive T cells. They may also be useful as predictive biomarkers or drug targets for human pregnancy disorders.

Ce résumé expose les affirmations des auteurs. BNTIC ne l’interprète pas comme une validation indépendante des résultats.